This invention relates, in general, to mechanical safety devices, and more specifically, to safing and arming devices which do not require stored energy.
Safing and arming devices are mechanisms which are used with fuzes on high explosive munitions. Fuzes, in turn, are designed to sense targets or the results of other prescribed conditions and initiate a train of fire or detonation in the munition. The safing and arming devices are designed to prevent premature activation of the fuze caused by extreme changes in heat or accidental impact.
Safing and arming devices of fuzes incorporated within Department of Defense (DoD) munitions are required to comply with strict safety requirements. Such requirements include the DoD's Safety Criteria for Fuze Design which specifies that the "fuze safety system should not utilize stored energy to remove safety features or provide arming energy unless no adequate environmentally derived energy is available". (MIL-STD-1316). Stored energy, for this purpose, includes batteries, springs having initial tension or compression, and explosives. Explosives are extensively used in munition fuzes because very few devices to date have been invented to utilize the limited electrical power available from environmental sources. Explosives are also the most dangerous stored energy source because heat from a fire (known as cook-off fire vulnerability), or accidental jarring, can cause the explosive to ignite.
Currently, the DoD is revising its safety criteria for fuzes (MIL-STD-1316) to eliminate all fuzes having any type of stored arming energy. One known device has been invented which utilizes only environmental energy. This device is described in a U.S. patent application by the same inventor as the present invention and assigned to the same assignee and entitled Safing and Arming Device having U.S. Ser. No. 431,253, now abandoned. However, this device works with a different action and is useful with different form factors and installation restraints.